This invention is directed to particular parts for road and off-road vehicle applications, particularly for internal combustion engines and other drive train parts for such vehicles. The unique construction of such parts of this invention comprise several plastic component parts so united as to form a continuous one piece part.
In the internal combustion engine field, particularly the automotive engine field, certain engines and drive train parts such as valve covers, oil pans, timing gear covers, transmission covers, intake manifold, and pinion gear housings are usually made of metal, and in some particular cases made from certain plastics. However, some of these metal covers or housings have poor sound deadening properties and can warp and/or rust over use requiring refinishing or ultimately new such metal housings. In the case of metal valve rocker covers, the air spout and inside baffle need to be welded to the cover, requiring an additional finishing operation. Even with thermoset molded valve covers, the oil spout and inside baffle need to be cemented or somehow joined to the valve cover, thereby requiring additional finishing operations. Glass filled polyamides (nylon) have also been used for molding such parts and are apparently currently in use, particularly for valve rocker covers. However, nylon, even glass filled nylon, has poor creep resistance, particularly operating at high automotive engine temperatures. Further, the nylons are not dimensionally stable, again, particularly over time at the high automotive engine temperatures.
Because of the need to reduce the overall weight of automotive vehicles, as well as reducing costs and increasing the life of automotive parts, there is a need for lighter weight, longer lasting and cost effective automotive engine parts.